SUMMARY ORDER

Appellants appeal from an order of the District Court denying the motion of the New York State Court Officers Association (the “Union”) for a preliminary injunction against the New York Unified Court System (“UCS”) and various state officials. We assume familiarity with the underlying facts and procedural history of this case.

This appeal arises out of a contract dispute between the Union and UCS, in which the Union alleged that UCS illegally and unconstitutionally reduced its rate of contribution to the Union’s health insurance premiums, in violation of the Contract Clause of the United States Constitution, U.S. Const. Art. I, § 10, and in violation of state law. The District Court conducted an evidentiary hearing on March 9, 2012, and thereafter issued an opinion and order denying the motion for preliminary injunction. The District Court held, inter alia, that the terms of the Collective Bargaining Agreement (“CBA”) unambiguously permitted UCS to reduce its rate of contribution to the Union’s health insurance plan to correspond with the rate being paid by the State to other state employee unions, and that a state law prohibiting such a reduction neither barred the reduction nor constituted an implied term of the contract.

On appeal, appellants allege that the District Court erred in: (1) treating the preliminary injunction sought by the Union as “mandatory” rather than “prohibitory,” and therefore requiring the Union to demonstrate a “clear or substantial likelihood of success” rather than merely a “likelihood of success”; (2) holding that the Union failed to prove a clear or substantial likelihood of success on the merits of its Contracts Clause claim; (3) finding that the CBA does not contractually obli *805 gate UCS to continue paying the same percentage of costs toward the health insurance of current Union members and retirees; (4) failing to hold that the laws governing state health plan contributions at the time the CBA was signed constituted implied terms of the CBA; (5) holding that N.Y. Civil Service Law § 167 does not create a contractual obligation for the state to continue paying health care contributions at the established rate; and (6) concluding that the legislature’s recent amendment to § 167 and promulgation of other related regulations does not substantially impair the Union’s contractual rights.

A district court may grant a preliminary injunction if the moving party establishes “(a) irreparable harm and (b) either (1) likelihood of success on the merits or (2) sufficiently serious questions going to the merits to make them a fair ground for litigation and a balance of hardships tipping decidedly toward the party requesting the preliminary relief.” UBS Fin. Servs., Inc. v. W. Va. Univ. Hosps., Inc., 660 F.3d 643, 648 (2d Cir. 2011). In reviewing a district court’s decision to deny a preliminary injunction, “we review the district court’s legal holdings de novo and its ultimate decision for abuse of discretion.” Cnty. of Nassau, N.Y. v. Leavitt, 524 F.3d 408, 414 (2d Cir. 2008) (citation and quotation marks omitted); cf. Sims v. Blot, 534 F.3d 117, 132 (2d Cir. 2008) (explaining that the term of art “abuse of discretion” includes errors of law).

CONCLUSION

We have carefully reviewed the record and the parties’ arguments on appeal, and we affirm the March 15, 2012 order of the District Court for substantially the reasons stated in its opinion and order of that date. 3 We remand the cause for such further proceedings as may be appropriate.